1. Field of the Invention
The present invention relates to an image processing apparatus and a 3D-shape displaying program, and more particularly, an image processing apparatus for displaying a 3D-shape employing a distinctive data structure as well as a program to be executed by the apparatus.
2. Description of the Background Art
As is well known, various expressions of objects, e.g., movements or rotations, have been made easier in the field of graphics. Above all, in the realm of games, expressions have been used such that a character can freely move in a region (hereinafter referred to as a “game field”) in which the character is allowed to move for game execution.
In general, this game field is represented as two-dimensional planes, and any objects formed on the planes, e.g., protrusions, are displayed on the basis of height information provided as attribute data of the plane coordinates. When a character moves in the game field, the height-wise position of a character is controlled with reference to the attribute data of the plane coordinates of a destination of a movement, thereby enabling the character to move along an object surface.
In recent years, there has been a desire for expressions of a game field which is displayed as a closed-surface 3D-object, e.g., the earth, such that a character can flexibly move along 3D-surfaces. This is tantamount to realizing game field expressions wherein continuing to proceed straight forward from a certain point results in returning to the same point.
However, according to the above-described conventional image processing technique, it is impossible to directly display a three-dimensional object because the game field is represented as two-dimensional planes. As for simple 3D-objects (e.g., hexahedrons), it may be possible to employ a pseudo-displaying method of joining a plurality of two-dimensional planes together. However, when this method is used, it would be necessary to subject the data of all two-dimensional planes to processing every time a character moves. Consequently, the processing time for obtaining the results would be increased and the processing time would vary, thus making this method impractical.